Improvement in mariners  compasses



2 Sheets-Sheet 1. E. S. RITCHIE.

Mriners Compass.

No. 38,125. Patented April 7, I863.

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2 Sheets-+She'et 2.

E. S. RITCHIE.

Marin'ers Compass.

Patented April 7, 1863.

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UNITED STATES PATENT, OFFICE.

EDWARD SAMUEL RITCHIE, OF BROOKLINE, MASSACHUSETTS.

IMPROVEMENT IN MARINERS CO'MPASSES.

Specification forming part of Letters Patent No. 38,125, dated April '7, 1863.

To all whom it may concern:

Be it known that I, EDWARD SAMUEL RITCHIE, a citizen of the United States of America, and a resident of Brookline, in the county of Norfolk and State of Massachusetts, have made a new and useful invention having reference to the Mariners Compass; and I do hereby declare that the same is fully described in the following specification and represented in the accompanying drawings, making part of such specification.

The purpose of the invention is not only to dispose of a mariners compass out of or more or less beyond the attractive influence of iron on or about the deck or other part of a ship or navigable'vessel, but to enable the movements or operations of the compass -card or the magnet or magnets of the compass to be easily read or indicated either at or near or below the deck or at any convenient distance below the compass.

My said invention is applicable to liquidcompasses, and particularly to such as are provided with an air-vessel combined with the magnet or the same and its card in manner so as not only to encompass the magnet and insulate it from the surrounding liquid, but also to buoy up the magnet or magnets and card in order to remove more or less of the weight thereof from the supporting pivot or bearing.

The nature of my said invention consists in the combination of an auxiliary air vessel or indicator and a connecting-rod or mechanical equivalents therefor with the magnet or magnets, or the same and its or their buoyant airvessel, the whole being arranged within a case or vessel to contain water or other proper fluid, and so as to operate together substantially as hereinafter specified.

And the nature of my invention further consists in the combination of either or both of the buoyant air-vessels with their shaft by means of gimbals or their mechanical equivalents.

And the nature of my invention further consists in the combination of an auxiliary buoyant chamber or its equivalent with the said connecting-rod or connector, the magnet, (or the same and its buoyant case,) and the auxiliary case or indicator, as arranged within a vessel or case containing a liquid, and so as to operate therein substantially as hereinafter specified.

And the nature of my invention further consists in a peculiar arrangement of the cardinal divisions or indications with respect to the float or indicator, when made substantially as specified.

And myinvention furtherconsists in the combination and arrangement of a hollow globe, open .at top and bottom, and its supportinggimbals with the water case or vessel and the magnet buoyant air-vessel therein.

And my invention further consists in an improved or elongated magnet air-vessel and with the magnet or magnets arranged lengthwise with respect to the same.

And my invention further consists in the combination of two or more buoyant radial floats or arms with the elongated magnet-vessel, the said arms or floats being for the purpose of giving stability in lateral directions to the magnet-float while submerged.

And my invention further consists in the combination of a graduation -ring with the radial-armed float, its connecting-rod, and the magnet-float, when arranged and combined within a water-vessel in manner and so as to operate substantially as described.

Of the drawings above mentioned, Figure 1, Sheet 1, denotes my invention or apparatus in side elevation, while Fig. 2 represents a vertical, central, and longitudinal section of it. Fig. 3 is a top view of themagnet buoyant vessel, the vertical connecting shaft or rod, and a set of gimbals connecting the two. Fig. 4 is a top View, and Fig. 5 a side elevation, of the auxiliary float or indicator. Fig. 6 is a horizontal section of the magnet float or buoy.

Fig. 7 is a vertical section of the needle-float.

Fig. Sis a horizontal section of the needle-float, its surrounding hollow globe, the gimbals, and the outer vessel thereof.

' The drawings of the auxiliary sheet, or that marked Sheet 2, represent another mode of constructing my invention or certain parts thereof, particularly the magnet air-vessel and the air-vessel on which the compass gradua,

tions are placed. The figures of the said Sheet 2 correspond to the first six figures of Sheet l--that is, Fig. l of Sheet 2 is a side elevation, and Fig. 2 a vertical section, of the apparatus. Fig. 3 is a top View ofits magnet buoyant airvessel, the vertical connecting shaft or rod, and the gimbals connecting the two. Fig. 4 is a top view, and Fig. 5 a side elevation, of its aux iliary float or indicator. Fig. 6is a horizontal section of the magnet float or buoy.

The external vessel or case, A, as shown in the drawings, may be supposed to be composed of two hollow and closed vessels, at b, and a tube, 0, connecting the bottom of one-via, a-with the top of the other-via, b oi: them, and opening into both of them in order that water or a fluid, when passed into the upper vessel, a, may pass freely through the tube 0, and from thence into the vessel b. The said vessel b, I usually construct cylindrical in form, and with its sides of a transparent materialsnch as glass, for instance-in order that the contents of such vessel 1) may be seen by looking through its sides. These two vessels at b and the tube 0 are to contain water or other suit- I able liquid, which should flll them as well as their connecting-pipe.

In Fig. 1, Sheet 1, I have exhibited a vessel or hollow globe, A, as fixed on the top of the vessel a and opening into it. The purpose of the additional vessel A is to allow either of the expansion or contraction of the liquid of the case A, such as arises from ordinary changes of atmospheric temperature.

A red or shaft, B, extends axially within the case A, and is pivoted or supported by suitable bearings at its two extremities, the same being shown at d d in Fig. 2. This shaft may be tubular, or be composed in part of a tube, 0, closed at its two ends and constituting an air chamber or vessel of sufficient capacity to buoy the shaft in th,e.liquid of the vessel A in such manner as to cause it to bear with little or no pressure on its lower pivot or bearin By constructing the shaft tubular and buoyant, as specified, it is not liable to be bent or sagged when the apparatus is in an inclined position or during the motions of a ship while the said apparatus may be in use on board thereof.

Within the vessel 0, and concentric with the shaft B, there is a float, buoy, or buoyant vessel, D, within which there. should be arranged one or more bar-magnets,g. (See Fig. 6.) In Figs. 6, 7, and 8 of Sheet 1, the said vessel D is represented as having the forrnot' a cylinder of a length considerably greater than its diameter, and also as provided with two lateral radial arms or buoyant chambers or vessels, or a the purpose of such arms being to give to the vessel D stability in lateral directions in the liquid contained in the part a of the case A.

The object of making the air-vessel D of the elongated form, whether such he cylindrical or polygonal in transverse section, is to reduce itto such a shape as will enable the liquid surrounding it to exercise against it the least disturbing action calculated to move it with its magnet out of the true meridianal direction. The elongated form I have found by practical experience to be much preferable to the annular or cylindrical ring-vessel, as shown in Figs. 2, 3, and 6 of Sheet 2.

In Figs. 2 and 8 of Sheet 1 I have represented a hollow globe, N, as arranged concentrically within the vessel to, and as-connected to it by gimbals, as shown atc This interior globe should have a large opening both at top and bottom, as shown at d e in Fig.2. These openings permit the passage of the shaft B through the said vessel b and also permitthe motions of the globe in its various directions without contact with the shaft. The object of this globe band its connection with the vessel a by gimbals is to prevent the rotary motion of the liquid inclosed by it during the oscillations of the case A. During such oscillations there will belittle or no movement of the equator of the globe out of its true horizontal position, and consequently the friction of the globe on thecontained liquid will have little tendency to produce rotary motion of the said liquid and the magnet-vessel within it. There is also another such float or buoyant vcssel,E, arranged within the vessel 1), and in a similar manner with respect to the shaft B. Each of the said floats D E is to be connected with the shaft B by a set of gimbals, h. There is to be no magnet within the vessel E whose buoyant power should be sufficient or about so to counterbalance the tendency of the said vessel and set of gimbals to sink downward in the fluid of the vessel 1). The buoyant power of the float D should sufflce also to counterbalance the tendency of it and its set of gimbals to sink in the fluid of the vessel 01.

The vessel E is furnished with radial lateral arms a a and it and such arms are surrounded by and fixed to a thin annulus or ring, f on whose outer periphery the cardinal divisions are to be formed, such'being shown in Fig. 5. Furthermore, when the vessel E is formed as shown in Sheet 2, I make on either the upper or under surface of it or down along its external curved surface or periphery cardinal divisional-marks indicative of the points of compass, the same being as shown in Figs. 4 and 5 of said Sheet 2.

I do not confine my invention to the particular form of the indicator E, as it may be otherwise constructed and yet serve its main purpose or objectviz., that of indicating the movements and positions of the magnet orv magnets. Nor is it essential to my invention that either of the parts D E should be made as a hollow vessel, as there are other ways in which it may be constructed and yet perform its function.

The tube 0 may be of any length which, according to circumstances, maybe necessary to carry the magnets for all practical purposes a sufficient distance above any metallic body which may be at or near the deck or; nyother part of a navigable vessel.

When in use my apparatus is intended to be afflxed to the mast or some other suitable part of a ship or navigable vessel, and so that, while the part b may be sufficiently near the deck to allow of the divisions on the part E being readily seen by a person when on deck, the part a may be at such an altitude above the deck as will practically remove the magnets out of the influence of the attractive power of any iron on or near the deck.

It will be observed that during the rolling as well as during the pitching motions of the ship the two floats or air-vessels D E, by the operation of gravity, will preserve their horizontal positions, and this notwithstanding their connector or shaft B may be inclined more or less to the horizon in the meantime. The gimbals and the shaft constitute such a connection of the parts D E that any rotary motion of the upper one occasioned by its magnet or magnets will be attended by a corresponding movement of the lower one, or that marked E.

In constructing the apparatus I prefer to make the magnet buoyant vessel the tubular part of the shaft or axis, and also the lower buoyant vessel or indicator in such manner that each, as nearly as practicable, shall be of the same weight as the volume of liquid displaced thereby.

Having thus described myinvention, what I claim is as follows:

1. The combination of the auxiliary air-vessel or indicator E and the connecting-rod B, or mechanical equivalents therefor, with the magnet or magnets g, or the same and its or their air-tight or buoyant case D, the whole being arranged within the vessel or case A to contain water or other proper fluid, and so as to operate together substantially as above specified.

2. The combination of either or both the buoyant air-vessels D E with their shalt or rod B by means of gimbals h, or their mechanical equivalents, the shaft or rod B being arranged and supported within a case, A, substantially in manner and so as to operate as described.

3. The combination of an auxiliary buoyant vessel, 0, or its equivalent, with the rod orconnector B, the magnet or the same audits buoyant case D, and the auxiliary case orindicator E, as arranged withina case or vessel, A, containing Water or other suitable fluid, and so as to operate therein substantially as hereinbefore specified.

4. The improvement of arranging the cardinal divisions on the external periphery of the circular indicator E substantially as specified.

5. The combination and arrangement of a hollow globe, b open at top and bottom, and its supporting-gimbals with the water case or vessel a and the magnet buoyant air-vessel therein.

6. The magnet air-vessel as made of an elongated form, and as having its magnet or magnets arranged lengthwise within it, substantially as represented in Figs. 6, 7, and 8 of Sheet 1, and as hereinbefore specified.

7. The combination of two or more buoyant radial floats or arms, a of, with the elongated magnet-vessel, the said arms being for the purpose hereinbefore stated.

8. The combination of a graduation-ring), with the radial-armed float E, its connectingrod B, and the magnet'float D, when arranged and combined within a water-vessel, A, in manner and so as to operate substantially as described.

. EDWD. S. RITCHIE.

Witnesses:

R. H. EDDY, F. P. HALE, Jr. 

